This excellent BBC documentary shows what a good documentary should contain. Though there are shortcuts ("cleared to taxi..." - takeoff shot!) it's remarkably good at showing the breadth of the job of practising and putting on a display, and shows both answers to the usual questions and answers to questions people probably wouldn't think to ask. It also, for once, shows what the ground crew do (John, as he says here, was a former RAF fitter himself) and it's a much better than usual effort in doing that, too.
Filming quality is remarkable - no tiny high-def GoPros here, but larger, unwieldy professional tape or film cameras; the Gnat's cockpit is tiny at the best of times - a camera inside at 2.5 to 4 g would be very challenging.
Some aspects have changed a lot, but the core of what the Reds specifically, and display teams in general, haven't changed in the last forty years. You can also see some of the foundations laid for the team by previous leader, the late, incomparable Ray Hanna. On which, more later...
BBC link: http://www.bbc.co.uk/archive/aerialjourneys/5328.shtml